Filling elements for filling machines are known in various different embodiments and consist essentially of a filling element housing having at least one liquid channel that is connected to a tank for providing the liquid product or filling material, or a component of this product or filling material, and at least one discharge opening for the controlled dispensing of the filling material into the container to be filled (e.g. into a bottle) as a function of the activation of a filling or liquid valve disposed in the liquid channel.
In particular it is known for filling elements to be provided at their discharge opening, or in the direction of flow of the filling material before the discharge opening, with gas barriers that, after the end of the particular filling operation and after the liquid valve closes, prevent the filling material from continuing to flow or drip from a partial space of the filling element, the partial space being formed by a section of the liquid channel downstream of the liquid valve in the direction of flow of the filling material.
With known filling elements, these gas barriers are usually executed as strainer-like inserts forming a plurality of strainer or flow channels for the liquid filling material, with the number and size of individual surfaces of the cross-sections of the flow channels being selected so that, when the liquid valve is closed, the filling material is held back in the partial section of the liquid channel by its surface tension in interaction with the ambient pressure. As a result, filling material does not continue to flow or drip through the gas barrier.
All known gas barriers have the disadvantage that they clog up frequently during the filling of products, for example drinks, that have solid constituents or suspended solids, such as pulps, fibers (including fruit fibers) etc. This is due, among other things, to the fact that the strainer-like structure necessarily forms webs or surfaces or structures that run square to the direction of flow or main direction of flow of the filling material and on which more solid constituents (solids, such as pulp, fibers including fruit fibers etc.) become lodged. This disadvantage is particularly noticeable when the filling material contains very long fibers that wrap themselves around, for example, the cross-webs formed by the strainer-like structure, thereby very rapidly constricting the flow cross-section of the gas barrier that is in use, and ultimately blocking it. Consequently the known gas barriers only permit the reliable processing of products with small solid particles.